Composition and method for diminishing the flow of water into permeable strata

ABSTRACT

A method and composition for treating porous formations through which water is escaping from ponds, canals, etc., said method utilizing a stable colloidal dispersion of a water-soluble, synthetic organic polymeric polyelectrolyte and a water-insoluble inorganic solid.

United States Patent [191 Routson Feb.5,1974

[ COMPOSITION AND METHOD FOR DIMINISHING THE FLOW OF WATER INTOPERMEABLE STRATA [75] Inventor: Willis G. Routson, Walnut Creek,

Calif.

[73] Assignee: The Dow Chemical Company,

Midland, Mich.

[22] Filed: Aug. 3, 1972 21 Appl. No.: 277,764

Related U.S. Application Data [63] Continuation-impart of Ser. No.44,609, June 8,

1970, Pat. No. 3,687,200.

[52] U.S. Cl. 61/1 R, 61/36 R [51] Int. Cl E021) 3/00 [58] Field ofSearch. 61/36 R, .5; 166/295; 106/33,

[5 6] References Cited UNITED STATES PATENTS 3,677,987 7/1972 Pence61/36 R 3,396,790 8/1968 Eaton 166/300 3,064,436 1 H1962 Loofbourow eta]. 61/.5

Primary ExaminerMervin Stein Assistant ExaminerA1ex Grosz Attorney,Agent, or Firm.l. R. Lochhead 5 7] ABSTRACT 10 Claims, N0 DrawingsCOMPOSITION AND METHOD FOR DIMINISHING THE 'FLOWOF WATER INTO PERMEABLESTRATA.

SUMMARY OF THE INVENTION The present invention is directed to employingcertain colloidal compositions for controlling the flow of aqueousfluids into permeable formations. More particularly, the inventioninvolves methods employing compositions comprising aqueous dispersionsof the reaction product of certain organic polymeric polyelectrolytesand a colloidal, water-insoluble, inorganic compound, and especiallymethods employing such compositions for treating porous formations.

More particularly, the invention is a method for plugging leaks inpermeable zones of, for instance, dams, canals, ponds, settling basins,lakes and the like.

In plugging such permeable zones, the colloidal dispersion may begenerated and placed in a position to be carried into the porousformation or channels by the natural flow of water through the leakingzone. In one method'of operation, the colloidal dispersion compositionis prepared in a solution of sufficiently high specific gravity so thatthe composition can be-allowed to flow down the upstream face of the damand thereby seek-out andpenetrate the zones wherein leakage isoccurring. In another method, the colloidal dispersion compositionisadded directly to the body of water itself, wherein it is carried intothe leaking zone with the escaping water.

The invention further comprises a stable colloidal dispersion of awater-soluble, synthetic organic polymeric polyelectrolyte and awater-insoluble inorganic solid suitable for controlling the mobility ofaqueous fluids in permeable formations or zones.

DETAILED DESCRIPTION OF THE INVENTION In their broadest scope, thecompositions of the present invention are those aqueous dispersionswherein a stable colloidal dispersion of a water-insoluble inorganicsolid is formed in an aqueous solution of a watersoluble, syntheticorganic polymeric polyelectrolyte, wherein said polyelectrolyte wouldnormally flocculate said inorganic solid if the dispersion thereof hadnot been formed in the presence of said polyelectrolyte and wherein thefinished aqueous composition is characterized by a resistance factorgreater than the resistance factor for an aqueous solution containingthe same concencentration of polymeric polyelectrolyte withoutsaidinorganic solid. For a definition of resistance factor, see myaforementioned co-pending Application and, also, U.S. Pat. No.3,399,725.

In general the organic polymeric polyelectrolytes employed in thecompositions of thepresent invention are known flocculating agents forfinely divided, waterinsoluble, inorganic solids. Thus, it would beexpected that the addition of a dilute solution of one of the organicpolymeric polyelectrolytes to a colloidal dispersion of water-insolubleinorganic solids would result in the flocculation and agglomeration ofsaid solids. Surprisingly, however, when a colloidal dispersion of oneof the water-insoluble inorganic solids of the invention is formed in asuitable aqueous solutionof one of said organic polymericpolyelectrolytes, flocculation and agglomeration do not occur, butinstead a stable, aqueous dispersion composition is obtained. Dependingupon the concentration and nature of the polymeric polyelectrolyte andof the particular colloidal inorganic solid employed, the aqueousdispersion compositions of the invention may vary in consistency fromliquids somewhat more viscous than the polymer solutions used in theirmanufacture to thick slimes or pultaceous gels. In any case, however,the compositions are adapted to flow into porous subterranean formationswith escaping water and, for such use, are characterized by resistancefactors which are increased with respect to the polymer solutions fromwhich the compositions are prepared. Preferred inorganic solids for usein the compositions of the invention include the sulfides of iron,copper, nickel, mercury, zinc, cadmium, cobalt, tin and lead and thehydroxides of aluminum, chromium, iron, cadmium, cobalt, manganese,nickel, copper, tin and zinc. Most preferred are the hydroxides ofaluminum and zinc.

The exact physical nature of these so-called colloidal dispersions isnot completely understood. There appears to be an interaction of theinorganic compound with the polymeric polyelectrolyte causing markedeffects on the rheological properties of the finished dispersion.

The water-soluble, synthetic organic polymeric polyelectrolytes employedin the composition of this invention are in general known flocculatingagents characterized as substantially linear, high-molecular-weightpolymers having sufficient polar groups in or along the polymer chain torender the polymer water-soluble. In the present context, high molecularweight polymers are those having weights of at least about one million,and preferably over two million. In practice it is preferred to employwater-soluble polymers characterized by a viscosity of at least 4centipoises, preferably at least 12 centipoises, for a 0.5 percent byweight solution of the polymer in distilled water at 25C. Representativepolymeric polyelectrolytes useful in the invention are water-solublepolymers of acrylamide, acrylic acid, sodium styrenesulfonate and thelike, and copolymers of such monomers with each other or with othersuitable monoethylenically unsaturated monomers such as ethylene,propylene, styrene, methacrylic acid, methacrylamide, vinyl alkanoicesters, vinyl chloride, maleic anhydride and the like. Other suitablepolymeric polyelectrolytes are the polymers and copolymers ofsodiosulfoalkyl acrylates and methacrylates, aminoalkyl acrylates andmethac'rylates and water-soluble salts of copolymers of maleic anhydridewith a vinyl-aromatic compound. The preferred polymeric'polyelectrolytesare high molecular weight polyacrylamides and hydrolyzedpolyacrylamides.

In preparing the compositions of the invention any suitable method forgenerating the colloidal, waterinsoluble, inorganic compound may beemployed provided said compound is formed in an aqueous solution of thewater'soluble organic polymeric polyelectrolyte. In one method ofproducing the water-insoluble inorganic compound, a double decompositionreaction is employed. For example, a soluble compound embodying asuitable anion, such as a sulfide or hydroxide ion, is dissolved in anaqueous solution of a polymeric polyelectrolyte and an aqueous solutionof a salt of a metal precipitatible by said anion is added theretogradually and with sufficiently vigorous mixing to avoid excessive localconcentrations of metal ions in the mixture. Alternatively, thecolloidal inorganic compound can be formed in a solution of a polymericpolyelectrolyte by an oxidation or reduction reaction, by altering thepH of a suitable metal salt solution or by ion exchange with a chelatedmetal ion. In order to illustrate the latter, one could, for instance,prepare a first solution of 18.3 mls. of lactic acid in 30 mls. of NNaOH. To two parts of this solution is then added one part of 25% A1 (SO9ul. of this solution, then, when added to 50 ml. ofa 1000 ppm. solutionof polyacrylamide results in the dispersion of the instant invention.

In practice, the compositions are generally produced by first preparing(by known methods) a dilute solution of one of the organic polymericpolyelectrolytes in water or in a suitable inert salt solution andadding thereto a precipitant, such as hydrogen sulfide or sodiumsulfide. To the resulting solution a dilute solution of a salt of ametal precipitatible by said precipitant is added gradually withstirring to form the colloidal, water-insoluble inorganic compound inthe presence of the polymeric polyelectrolyte. Thus, for example, a highmolecular weight, water-soluble polyacrylamide or hydrolyzedpolyacrylamide is dissolved in aqueous 3 percent sodium chloride brineto produce a solution containing at least about 0.005 percent by weight,and preferably from about 0.01 to about 0.50 percent by weight, ofpolymer and sufficient sodium sulfide is dissolved in the resultingsolution to provide from about 2 to about 5 parts by weight of sulfideion per million parts by weight of solution. To the sulfide-containingpolymer solution there is added dropwise with stirring a dilute aqueoussolution, generally containing from about 0.05 to about 0.2 percent byweight of metal ion, ofa soluble salt ofa metal which forms an insolublesulfide, as, for example, a salt of iron, copper, nickel, mercury, zinc,cadmium, cobalt, tin or lead, to produce a stable colloidal dispersionof the corresponding insoluble metallic sulfide. Similarly, a smallamount of an alkali metal hydroxide or of an alkaline buffer can bedissolved in the polymer solution and thereafter a dilute solution of asuitable metallic salt, such as a soluble salt of aluminum, chromium orzinc, is added to precipitate the corresponding metal hydroxide, suchas, respectively, aluminum, chromium or zinc hydroxide, in the form of astable, colloidal dispersion of the insoluble metal hydroxide. In largescale operations, the polymer solution containing the anionicprecipitant can be prepared batchwise or continuously and the metallicsalt solution may be pumped into a stream of the polymer solution in asuitable conduit wherein natural or induced turbulence provides forproper mixing to generate the desired colloidal dispersion of insoluble,inorganic compound in the flowing stream of polymer solution. In thismanner, the colloidal dispersion can be formed in situ immediatelybefore utilizing same on the dam or canal face, or before introductioninto the body of water itself.

In certain cases it is convenient to prepare compositions of theinvention wherein the colloidal inorganic compound is generated in thepresence of the polymer by more complex reactions, such as oxidation orreduction. For example, it has been found that compositions embodyingchromic hydroxide are conveniently prepared byadjusting the pH of asuitable solution of polymeric polyelectrolyte to a value in the rangeof 6.5 to 8.5, and adding an alkali metal chromate to the solutionfollowed by a strong reducing agent such as sodium hydrosulfite togenerate chromic ions in situ, which then form the desired colloidalchromic hydroxide sol. Alternatively, hydroxide precipitates can beformed by first adjusting the pH of the polymer solution to a low value,then dissolving a small quantity of a soluble salt of the metal to beprecipitated in said solution and thereafter adjusting the pH upwarduntil the desired metal hydroxide separates as a colloidal dispersioncomposition. The same effect can be obtained by dissolving an amphotericmetal to be precipitated in the solution at a high enough pH to keep itin solution, and thereafter reducing the pH until the desired metalhydroxide separates as a colloidal dispersion composition. When thewater used for diluting the solution is sufficiently buffered, it can beused to adjust the pH to cause the metallic hydroxide to precipitatefrom either the original acid or basic solution.

The concentrations of ingredients in the colloidal dispersioncompositions may vary depending upon the degree of fluidity desired andthe permeability and porosity of the formation to be treated. Ingeneral, the compositions should contain at least about 0.001 percent byweight of at least one organic polymeric polyelectrolyte and may containup to an amount of such polymer which precludes proper mixing of otheringredients by reason of the viscosity of the polymer solution.Preferably, the compositions contain from about 0.01 to about 1.0percent by weight of the polymeric polyelectrolyte. Any suitable amountof the colloidal, waterinsoluble, inorganic compound can be employedprovided such amount is sufficient to reduce or stop flow of water intothe permeable formation. In general, such finished compositions willcontain at least about 0.05 part by weight, and preferably from about 1part to about parts by weight, of colloidal, water-insoluble, inorganiccompound per million parts by weight of finished dispersion composition.The concentration of inorganic compounds in the finished composition is,of course, only a minor proportion of the concentration of the polymertherein.

SPECIFIC EMBODIMENTS EXAMPLE 1 The level of a water-storage pond behindan earthen dam in California has been dropping at an excessive rate dueto leaks near the base of the dam. An aqueous solution containing 500parts by weight of an acrylamide polymer per million parts of solutionis prepared in 0.3 percent sodium chloride brine. The polymer is apolyacrylamide having about 20 percent of the carboxamide groupshydrolyzed to carboxylate groups and is characterized by a viscosity ofabout 19 centipoises for a 0.5 percent by weight solution thereof inwater at a temperature of 25C. The polymer solution is pumped to theupstream face of the dam and, just before application, sufficientchromic chloride solution is mixed with the polymer solution to provide20 parts by weight of chromic ion per million parts of polymer solutionto form a colloid complex with the polymer.The resulting colloid complexcomposition is flowed down the upstream face of the dam in the areaswhere the leaks originate so that the flow of water will carry themetalpolymer complex composition into the permeable formation in the dambase. The following day it is found that leakage through the dam hasessentially ceased.

EXAMPLE 2 The level of a water-storage pond in California had beendropping at an excessive rate due to leaks. An aqueous solutioncontaining 1,000 parts by weight of an acrylamide polymer per millionparts of solution is prepared in pond water. The solution is pumpedthrough a 2 /2 inch hose to a storage tank on shore. Just beforeentering the tank, a solution of sodium aluminate is added. The pH ofthe resulting mixture is about 9.5, which issufficient to keep thesodium aluminate in solution. The final concentration of sodiumaluminate is such that the resulting solution contains 5 to parts byweight of aluminum ion per million parts of solution. The solution flowsout of the tank through a hose. Immediately after leaving the tank, anaqueous 12% solution of ammonium sulfate is added in such an amount toreduce the pH to 8.2. This causes hydrous aluminum hydroxide toprecipitate and coacervate with the dissolved polymer to form thecomposition of this invention. The solution is then pumped through ahose into a large mixing venturi made out of 4 inch diameter pipe. Theventuri is submersed in the pond, its purpose being to mix sufficientpond water into the stream of composition to dilute the polymerconcentration to 250 ppm or lower. The venturi is properly anchoredhorizontally near the side of the lake so that its force encourages theentire mass of water in the pond to circulate. A motor boat was alsoanchored to shore in such a position that the motor helped the entirelake to circulate. The solution at 250 ppm is dilute enough so that itdistributes easily into the total mass of water in the pond. Thepermeable formations through the pond bottom are thus exposed to thepolymer-metal ion complex. The leakage rate gradually decreases as thiscomplex enters the flow passages and plugs them.

l claim:

1. The method for plugging leaks in permeable zones of earthen dams,canals, ponds, settling basins and lakes comprising contacting said zonewith a stable colloidal dispersion of a water-soluble, inorganic solidformed in an aqueous solution of a water-soluble, synthetic organicpolymeric polyelectrolyte by placing said dispersion in a position to becarried into said permeable zone by the natural flow of water throughsame.

2. A method according to claim 1 wherein the polymeric polyelectrolyteis employed at a concentration of at least about 0.001 percent by weightof the total composition.

3. A method according to claim 2 wherein said concentration is fromabout 0.0l to about 1.0 percent by weight.

4. A method according to claim 1 wherein the inorganic solid is employedat a concentration of at least about 0.05 part by weight per millionparts of total composition.

5. A method according to claim 1 wherein the inorganic solid is a metalsulfide, said metal being iron, copper, nickel, mercury, zinc, cadmium,cobalt, tin or lead; or a metal hydroxide, said metal being aluminum,chromium, iron, cadmium, cobalt, manganese, nickel, copper, tin or zinc.

6. A method according to claim 1 wherein the polymeric electrolyte ispolyacrylamide or a hydrolyzed polyacrylamide.

7. A method according to claim ll wherein the poly meric electrolyte ispolyacrylamide or a hydrolyzed polyacrylamide and the inorganic solid isa sulfide of iron, copper, nickel, mercury, zinc, cadmium, cobalt, tinor lead, or a hydroxide of aluminum, chromium, iron, cadmium, cobalt,manganese, nickel, copper, tin or zinc.

8. A method according to claim 7 wherein the inorganic solid is aluminumor zinc hydroxide.

9. A method according to claim 1 wherein the colloidal dispersion isemplaced along the upstream face of an earthen dam and injected intoporous passages in said dam by the pressure of the water entering saidpassages.

10. A method according to claim 1 wherein the colloidal dispersion isplaced directly into the body of water, whereby it is carried into theporous formation with the water escaping through same.

2. A method according to claim 1 wherein the polymeric polyelectrolyteis employed at a concentration of at least about 0.001 percent by weightof the total composition.
 3. A method according to claim 2 wherein saidconcentration is from about 0.01 to about 1.0 percent by weight.
 4. Amethod according to claim 1 wherein the inorganic solid is employed at aconcentration of at least about 0.05 part by weight per million parts oftotal composition.
 5. A method according to claim 1 wherein theinorganic solid is a metal sulfide, said metal being iron, copper,nickel, mercury, zinc, cadmium, cobalt, tin or lead; or a metalhydroxide, said metal being aluminum, chromium, iron, cadmium, cobalt,manganese, nickel, copper, tin or zinc.
 6. A method according to claim 1wherein the polymeric electrolyte is polyacrylamide or a hydrolyzedpolyacrylamide.
 7. A method according to claim 1 wherein the polymericelectrolyte is polyacrylamide or a hydrolyzed polyacrylamide and theinorganic solid is a sulfide of iron, copper, nickel, mercury, zinc,cadmium, cobalt, tin or lead, or a hydroxide of aluminum, chromium,iron, cadmium, cobalt, manganese, nickel, copper, tin or zinc.
 8. Amethod according to claim 7 wherein the inorganic solid is aluminum orzinc hydroxide.
 9. A method according to claim 1 wherein the colloidaldispersion is emplaced along the upstream face of an earthen dam andinjected into porous passages in said dam by the pressure of the waterentering said passages.
 10. A method according to claim 1 wherein thecolloidal dispersion is placed directly into the body of water, wherebyit is carried into the porous formation with the water escaping throughsame.